Cosmology & Gravitation

We apply CMB lensing techniques to large scale structure
and solve for the 3-D cosmic tidal field. We use small scale filamentary
structures to solve for the large scale tidal shear and gravitational
potential.

When recent observational evidence and the GR+FRW+CDM
model are combined we obtain the result that the Universe is accelerating,
where the acceleration is due to some not-yet-understood "dark
sector". There has been a considerable number of theoretical models
constructed in an attempt to provide an "understanding" of the dark

Fluctuations in the cosmic
microwave background (CMB) contain information which has been pivotal in
establishing the current cosmological model. These data can also be used to
test well-motivated additions to this model, such as
cosmic textures. Textures are a type of topological defect that
can be produced during a cosmological phase transition in the early universe,
and which leave characteristic hot and cold spots in the CMB. We apply Bayesian
methods to carry out an optimal test of the texture hypothesis, using

Cosmological
birefringence is a postulated rotation of the linear polarization of photons
that arises due to a Chern-Simons coupling of a new scalar field to
electromagnetism. In particular, it appears as a generic feature of simple
quintessence models for Dark Energy, and therefore, should it be detected,
could provide insight into the microphysics of cosmic acceleration. Prior work
has sought this rotation, assuming the rotation angle to be uniform across the
sky, by looking for the parity-violating TB and EB correlations in the CMB